摘要
气流调制技术产生次声具有发声强度高、声波频率可控的特点。对基于气流调制的封闭空间高声强次声产生装置开展了实验研究。研究了双舱声信号的异同、测试舱的频响特性和谐波情况,还研究了舱外次声及其谐波的传播衰减情况。实验结果表明:测试舱内次声波的基频强度比其2次谐波的强度要大40dB以上,失真较小。排气管在舱外产生的次声在传播过程中衰减很快,波形的非线性失真严重,大多数能量向其谐波转移,8Hz频率成分的2次谐波强度比其基频大20dB以上。
The airflow modulator can generate the high-intensity infrasound with controllable frequency. Some experimental studies of the high-intensity infrasound generator in the close space were carried out, including the difference between the sound wave for double chambers, the characteristics of the frequency response and its harmonics in test chamber, as well as the atten- uation of infrasound and its harmonics outside the test chamber. The experimental results show that the intensity of the funda- mental frequency is more than 40dB larger than its second harmonic and the distortion is very little. The infrasound generated by the vent-pipe outside the test chamber is attenuated rapidly with the increase of the distance in outdoor. There is severe non- linear distortion in its waveform and most of the energy was transferred to its harmonics. The intensity of the second harmonic of the 8Hz is more than 20dB larger than that of its fundamental frequency.
出处
《振动工程学报》
EI
CSCD
北大核心
2013年第3期404-410,共7页
Journal of Vibration Engineering
关键词
次声
气流调制器
赫尔姆霍兹共振器
声学特性
声压级
infrasound
airflow modulatorl Helmholtz resonator
acoustic eharacteristicl sound pressure level （SPL）
